Higher order numerical schemes for SPDEs with additive Noise
Abhishek Chaudhary, Andreas Prohl
TL;DR
The paper develops high-order numerical schemes for linear SPDEs with additive noise by transforming the SPDEs into random PDEs and applying a modified Crank–Nicolson approach. For the stochastic heat equation, the scheme achieves a strong convergence rate of $\mathcal{O}(\tau^{3/2})$ under sufficiently smooth data, while for the stochastic wave equation the corresponding scheme attains a rate of $\mathcal{O}(\tau^{2})$. These results rely on enhanced temporal regularity of the transformed solutions and a hybrid quadrature strategy that treats deterministic and stochastic integrals on appropriately refined meshes. Numerical experiments on $D=(0,1)$ corroborate the theoretical rates, demonstrating substantial improvements over standard Euler-type schemes and validating the practicality of the proposed methods for general elliptic operators $A$.
Abstract
We present high-order numerical schemes for linear stochastic heat and wave equations with Dirichlet boundary conditions, driven by additive noise. Standard Euler schemes for SPDEs are limited to an order convergence between 1/2 and 1 due to the low temporal regularity of noise. For the stochastic heat equation, a modified Crank-Nicolson scheme with proper numerical quadrature rule for the noise term in its reformulation as random PDE achieves a strong convergence rate of 3/2. For the stochastic wave equation with additive noise a corresponding approach leads to a scheme which is of order 2.
